HANNA PHOTOMETER REAGENTS · HI93750
Two potassium ranges. One matched reagent set.
Replenish the liquid-and-powder chemistry for both HI97750 potassium ranges. The same 100- or 300-test set serves low-range testing and the documented diluted medium-range workflow—there is no separate MR reagent pack to select.
Official Hanna potassium-page bottle reference image, not a photograph of the complete A/B contents. Printed lot and expiry markings are illustrative, not supplied-stock dates.
Match the method, not just the element name
HI97750: LR 0.0 to 20.0 mg/L as K; MR 10 to 100 mg/L as K. The turbidimetric tetraphenylborate method intentionally develops turbidity. On HI97750, the LR range is 0.0 to 20.0 mg/L as K and MR is 10 to 100 mg/L as K. The instrument can also display potassium oxide (K₂O); the ranges quoted here are as K, not as K₂O.
What the selected pack supplies
A complete potassium set containing liquid reagent A and powder reagent B for 100 or 300 determinations. Both HI97750 ranges use 6 drops A and one B packet. HI93703-51 dispersing agent is not part of the documented HI97750 procedure; no additional dispersing step is required.
Where this method fits
A practical refill for water and nutrient-monitoring programs that specify potassium concentration. Use the instrument’s selected range and matching dilution procedure. The supplier’s broader reagent-use range is not the HI97750 range; do not extend this instrument to 200 mg/L as K.
The HI97750 workflow at a glance
Select Potassium LR and fill the cuvette with 10 mL of sample. Add 6 drops of A, stopper and cap, swirl and zero with the cap notch aligned. Add one packet of B, stopper, cap and shake gently for 1 minute. Use the 3-minute countdown; after it has passed, invert 5 times, return the aligned cuvette and press Read twice. For MR, select Potassium MR and first dilute exactly 20 mL of sample to 100 mL in a volumetric flask with deionized water; then run the same additions on 10 mL of that dilution.
Check the sample matrix
The manual lists chloride above 12000 mg/L, calcium above 10000 mg/L as CaCO₃, magnesium above 8000 mg/L as CaCO₃, sodium above 8000 mg/L and ammonium above 10 mg/L as potential interferences. Check the sample matrix rather than assuming unrestricted brine or seawater suitability.
Choose a pack around your workload
HI93750-01 supplies 100 tests; HI93750-03 supplies 300 tests. The larger pack supplies three times the determinations, not a different measuring range. One order quantity means one complete selected pack. Choose by testing frequency and the lot/expiry markings on supplied stock.
What to have beside the reagent set
Supply the compatible photometer, cuvettes with stoppers and caps, and the measuring/dispensing accessories required by the method separately. A volumetric flask and deionized water are required for potassium MR dilution. CAL Check standards are separate instrument-verification materials, not replacements for sample reagents.
Handling before you begin
Review both US SDS before use. Reagent A is flammable and carries serious toxicity, genetic and cancer hazards; B carries ingestion, inhalation and serious eye-damage hazards. Apply the specified controls and disposal practices. Hanna flags both pack sizes as Dangerous Goods for ground shipment only.
Use the linked HI97750 instrument manual as the method reference for the complete procedure, precautions and instrument operation. This is not a separate reagent instruction manual.
Frequently Asked Questions
Should I choose 100 or 300 tests?
HI93750-01 supplies 100 tests; HI93750-03 supplies 300 tests. Both are complete reagent sets for the same method. Choose by expected workload and marked expiry dates, not by a different analytical range.
Do LR and MR need different reagent packs?
No. Both HI97750 methods list the same HI93750-01 and HI93750-03 sets, using 6 drops of A and one packet of B. MR differs by its preliminary sample dilution and the range selected on the meter.
What dilution does medium range require?
Accurately add 20 mL of sample to a 100 mL volumetric flask and bring to volume with deionized water. Select Potassium MR, then use 10 mL of that prepared dilution for the documented A/B procedure.
Do I add HI93703-51 dispersing agent?
No dispersing-agent step appears in the HI97750 LR or MR method. The required reagents are only HI93750A-0 and HI93750B-0. Do not import a dispersing step from a different chemistry.
When should I remix before reading?
After adding B, shake gently for 1 minute, then wait the 3-minute countdown. Invert the cuvette 5 times after that wait, reinsert it with the cap notch aligned, and press Read twice for the result. The quoted HI97750 ranges are as K, not the optional K₂O display.
Which photometers are documented for HI93750?
Both packs are documented for HI97750. The procedure and range on this page use HI97750 as the primary reference; follow the exact instrument method when using another model.
Which sample conditions should I check first?
The manual lists chloride above 12000 mg/L, calcium above 10000 mg/L as CaCO₃, magnesium above 8000 mg/L as CaCO₃, sodium above 8000 mg/L and ammonium above 10 mg/L as potential interferences. Check the sample matrix rather than assuming unrestricted brine or seawater suitability.
Are the instrument, cuvettes and CAL Check standards included?
No. These are reagent-only packs. Provide the photometer, cuvettes with stoppers and caps, and the method-required sampling and dispensing accessories separately. CAL Check standards are separate instrument-validation materials, not test reagents.
